<template>
    <div style="display:flex">
        <el-select clearable placeholder="请选择省份" v-model="province">
            <el-option v-for="item in areas" :key="item.code" :value="item.code" :label="item.name">
            </el-option>
        </el-select>
        <el-select clearable :disabled="!province" style="margin:0 10px" placeholder="请选择城市" v-model="city">
            <el-option v-for="item in selectCity" :key="item.code" :value="item.code" :label="item.name">
            </el-option>
        </el-select>
        <el-select clearable :disabled="!province || !city" placeholder="请选择区域" v-model="area">
            <el-option v-for="item in selectArea" :key="item.code" :value="item.code" :label="item.name">
            </el-option>
        </el-select>
    </div>
</template>

<script lang='ts' setup>
import { ref, watch } from 'vue';
import allAreas from '../lib/pca-code.json'

export interface AreaItem {
    name: string,
    code: string,
    children?: AreaItem[]
}

export interface Data {
    name: string,
    code: string
}

let province = ref<string>("")
let city = ref<string>("")
let area = ref<string>("")

let areas = ref<AreaItem[]>(allAreas)
let selectCity = ref<AreaItem[]>([])
let selectArea = ref<AreaItem[]>([])

watch(() => province.value, val => {
    if (val) {
        let cities = areas.value.find(item => item.code === province.value)!.children!
        selectCity.value = cities;
    }
    city.value = ''
    area.value = ''
})

watch(() => city.value, val => {
    if (val) {
        let areas = selectCity.value.find(item => item.code === city.value)!.children!
        selectArea.value = areas
    }
    area.value = ''
})

let emits = defineEmits(['change'])

watch(() => area.value, val => {
    if (val) {
        let provinceData: Data = {
            code: province.value,
            name: areas.value.find(item => item.code === province.value)!.name
        }
        let cityData: Data = {
            code: city.value,
            name: selectCity.value.find(item => item.code === city.value)!.name
        }
        let areaData: Data = {
            code: val,
            name: selectArea.value.find(item => item.code === val)!.name
        }
        emits("change", {
            province: provinceData,
            city: cityData,
            area: areaData
        })
    }
})

</script>

<style lang='scss' scoped>
.el-select {
    display: inline
}
</style>